.box {
  width: 120px;
  height: 120px;
  box-sizing: border-box;
  position: relative;
}
.wifi-symbol {
  width: 50px;
  height: 50px;
  box-sizing: border-box;
  overflow: hidden;
  transform: rotate(135deg);
  position: relative;
  top: -6px;
  left: 20px;
}
.wifi-circle {
  border: 3px solid #fff;
  border-radius: 50%;
  position: absolute;
}

.first {
  width: 5px;
  height: 5px;
  background: #fff;
  top: 45px;
  left: 45px;
}

.second {
  width: 30px;
  height: 30px;
  top: 36px;
  left: 36px;
  animation: fadeInOut 1s infinite 0.2s;
}

.third {
  width: 40px;
  height: 40px;
  top: 29px;
  left: 29px;
  animation: fadeInOut 1s infinite 0.4s;
}

@keyframes fadeInOut {
  0% {
    opacity: 0; /*初始状态 透明度为0*/
  }
  100% {
    opacity: 1; /*结尾状态 透明度为1*/
  }
}